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-   -   496 HO - Remove Turbulator and Lost Speed? (https://www.offshoreonly.com/forums/general-boating-discussion/215267-496-ho-remove-turbulator-lost-speed.html)

CheckedOut 08-19-2009 02:49 PM

496 HO - Remove Turbulator and Lost Speed?
 
Has anyone removed the turbulators on their late model 496HOs and lost some speed?

tblrklakemo 08-19-2009 03:01 PM

I did it in my fountain and noticed no change up or down.

spectras only 08-19-2009 03:51 PM

Don't have 496's , but experimented on my 6.2's [ 377cu]
removing the turbulators on the port engine first. Didn't make any difference , rpm's [ speed] stayed the same. Same result for the starboard engine. The exh ports at the riser joints are small for both 496 and 377 , so the turbulator really doesn't make a diff in or out. Putting mufflers on or slip ins at the tips would affect rpm's at WOT , dropping as much as up to 200, hence loosing speed. The turbulators get red hot at high rpm's and burn up water droplets [ condensation ] while going down to idle while the engine cooling down. It's a Merc warranty issue .
An aftermarket exhaust manifold/riser and slightly more cam would be your best bet for some performance gains.

CheckedOut 08-19-2009 04:17 PM

Spectras, Thanks for the advice. Unfortunately, Considering that I would have to take the motors out anyway to install the headers, it would be a tough call to spend 10k on a set of headers when for roughly the same price I could drop in a set of 525s with around the same amount of hours. With a 525 I would pick up over twice the power gains and also leave room for improvement ala a Whipple kit which would last much longer on the better stock bottom end than on a 496. If i can get a better deal, I may think a little hard about it but given that the 496 needs ALOT of parts to really get where i want to be It will be cheaper in the long run to get another set of motors.

Keith Atlanta 08-19-2009 04:20 PM

$10K that is a stretch for Blue power... In this market you couldnt get more that $3000 a piece for used 496 HO's...

You can buy new 496 Mag HO's from IMCO for $5000!

Checked out - If you take the manifolds off and have them ported, you might pick up 100 RPM. A few people on OSO have been successful porting them. Even when I installed Stainless Marine Manifolds and reprogrammed the ECU I only picked up 150-200RPM.

CheckedOut 08-19-2009 04:31 PM


Originally Posted by Keith Atlanta (Post 2935170)
$10K that is a stretch for Blue power... In this market you couldnt get more that $3000 a piece for used 496 HO's...

You can buy new 496 Mag HO's from IMCO for $5000!


Wow that is rough........Considering that dealer cost is 14k. I would believe that when I see it. They probably dont have a warantee and were out of a repo or sunk boat.

spectras only 08-19-2009 04:46 PM

Checkedout, did you attend our Harrison Lake Poker run ?

CheckedOut 08-19-2009 04:51 PM


Originally Posted by spectras only (Post 2935190)
Checkedout, did you attend our Harrison Lake Poker run ?


No. Unfortunately. Maybe next year.

BrettM 08-19-2009 05:24 PM


Originally Posted by CheckedOut (Post 2935181)
Wow that is rough........Considering that dealer cost is 14k. I would believe that when I see it. They probably dont have a warantee and were out of a repo or sunk boat.

http://imcomarine.com/ca_store/index...roducts_id=835

Truck motor with some marine parts.

I just shopped all over for 496 HO's with warranty and paid more than I would have liked.

525's are higher in price then metioned as well from what I found.

jordy 08-19-2009 05:33 PM


Originally Posted by CheckedOut (Post 2935166)
Spectras, Thanks for the advice. Unfortunately, Considering that I would have to take the motors out anyway to install the headers, it would be a tough call to spend 10k on a set of headers when for roughly the same price I could drop in a set of 525s with around the same amount of hours. With a 525 I would pick up over twice the power gains and also leave room for improvement ala a Whipple kit which would last much longer on the better stock bottom end than on a 496. If i can get a better deal, I may think a little hard about it but given that the 496 needs ALOT of parts to really get where i want to be It will be cheaper in the long run to get another set of motors.

You answered your own question. For the few mph gains you'd get by changing exhaust, etc. with the 496's you'd be better off to save your pennies and hundies and go with some blue power. The 496 is a great engine if you leave it alone and let it run like it was designed to run. I know it's tempting to start tweaking on them in the never ending quest for more speed and power, but then reliability starts being sacrificed... which is more important?


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